Polymer microspheres prepared by the present invention have a hollow structure, the preparation methods of this type of polymer have been quite described in literatures and patents, the most commonly used emulsion polymerization reaction is via a two-stage core/shell emulsion reaction to get a polymer hollow microsphere emulsion, such as those revealed in U.S. Pat. Nos. 5,494,971 and 6,252,004, and on the other hand, to improve the temperature resistance, ROC Patent No. 1312355 describes that core cross-linking/shell without cross-linking or core/shell cross-linking are conducted in a two-stage preparation of hollow particles, the best situation is that the core is not cross-linked, while the reaction step of shell encapsulation is cross-linked. But its shortcomings: in the former, owing to core cross-linking, the core is not easy to turn into the hollow shape of core/shell particles in alkali swelling, in the latter, due to the particle core/shell interface compactness is loose and there is no intermediate buffer layer, in the follow-up process of alkali swelling, due to osmotic pressure, alkali molecules go into the internal core-shell particles and neutralize with the acidic core, and meanwhile the mutual repulsive interaction among ionic charges, and the hydrophilic property of the carboxyl ion is much larger than that of carboxylic acid, which has led to the molecular chain to migrate to the water external to particles, thus the particle size is further expanded, but due to hydrophobic and cross-linking processing to repel the increasing particle size, two kinds of inside and outside forces have been formed and squeezed continuously in the outer shell polymer. In addition, because the alkali molecules and the acidic cores conduct the neutralization reaction between acid and alkali to form ionic salts having a dissolution effect resulting in a structure of the hollow particles, and the particle shell is further thinned, and can not afford the aforementioned inside and outside pressure squeeze stress that leads to the hollow particle breakage. Because of the above mentioned two contradictions, it is difficult to synthesize the hollow particles with both the particle size and the hollow degree in accordance with demand and without damage.